Abstract:
The TRMM Composite Climatology (TCC) is a climatology (or map of mean values) of surface precipitation based on 13 years of data from the Tropical Rainfall Measuring Mission (TRMM). The TCC takes advantage of the information from multiple estimates of precipitation from TRMM to construct mean value maps over the tropics (36°N - 36°S) for each month of the year at 0.5° latitude-longitude ... resolution. The first-time use of both active and passive microwave instruments on board TRMM has made it the foremost satellite for the study of precipitation in the tropics and has led to a better understanding of the underlying physics and distribution of precipitation in this region. The TCC utilizes the TRMM multiple estimates to provide an answer to the overarching goal of TRMM: How much rain is falling in the Tropics? The TCC also includes estimates of the error for the mean values, constructed from a calculation of the variation among the input estimates. It is hoped that this new climatology will be useful to the user community as a ready comparison with other non-TRMM analyses and for comparison with numerical models, including those used for retrospective “re-analysis” and for climate simulations. It should also be useful as an educational reference for understanding tropical rainfall.

Purpose:
One of the main goals of the Tropical Rainfall Measuring Mission (TRMM) has been to accurately define the climatological surface rainfall in the tropics. This TRMM Composite Climatology (TCC) consists of a merger of selected TRMM rainfall products over both land and ocean to give a "TRMM-best” climatological estimate. Inputs to the composite were selected based on knowledge of the performance of ... the retrievals, limitations of the algorithms, and the presence of artifacts. Over ocean the rainfall estimates used for the TCC are from TMI (2A12), PR (2A25,near surface) and combined TMI-PR (2B31). Over land the rainfall estimates from the TRMM Multi-satellite Precipitation Analysis (TMPA, 3B43) are used to replace those from the TMI, because the land estimates from 2A12 (Version 6) are known to overestimate surface rainfall during the warm season. Other adjustments or quality control steps are taken, including adjusting the post-boost PR data to match the pre-boost (more sensitive) PR retrievals and eliminating small artifacts related to coastlines and islands. Maps of month-of-the-year climatologies of all four products (including adjustments and quality control steps) are then calculated at 0.5° latitude-longitude resolution from 36°N to 36°S, using twelve years (1998-2009) of TRMM V6 data. A simple mean of the three products (a different set of three over land and ocean) produces the final TCC estimate. In addition to the mean precipitation estimates, the TCC includes the variation among the three estimates (in terms of the standard deviation,σ) at each point to give an estimate of the error in the estimated mean value, at least in a relative sense. Details of the procedure and results and comparison with other data sets can be found in the reference below.

There are 78 data files in this TCC data directory: 13 each (annual and month-of-year) for 2A12, 2A25, 2B31, 3B43, TCC, and standard deviation of TCC. The file name means: type.month.TRMMversion.bin. Each file is one grid, and the grid is 0.5 degree. The data are from west to east starting from 0.25E (720 grids), and north to south starting from 35.75N (144 grids). Thirteen GIF files of TCC rainfall (12 months and annual mean) as well as a README file to help users reading the data are also included

Description:
Mirador is a simplified interface for searching, browsing, and ordering Earth science data at NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). Mirador is designed to be fast and easy to learn.

Description:
This tool is a prototype that allows visualization of the entire product suite with overlay of different parameters. Additional functions allow plotting scatter diagrams, time series, etc. See the FAQ for further usage on this tool. Questions and comments can be sent to gsfc-help-disc@lists.nasa.gov. The data will be ingested into the permanent archive and provided through our Mirador and other services here at the GES DISC, but can be accessed in a temporary ftp location until then at ftp://disc2.nascom.nasa.gov/data/TRMM/Gridded/TRMM_TCC.